Asset Allocation Drift Calculator
Deviation from target allocation triggering rebalance.
Calculate drift between current and target asset allocation to decide if rebalancing is needed. Enter equity to see drift percentage and rebalance flag.
What this tool does
Asset allocations drift over time as different assets perform differently. This calculator measures how far your current allocation has moved away from your target by comparing your current equity percentage to your target equity percentage. It then estimates the size of that deviation and indicates whether it has crossed your rebalance threshold—the point at which you might take action to realign your portfolio. The drift figure represents the percentage-point gap between where you are and where you intended to be. Results depend most heavily on the difference between current and target allocations, as well as the threshold you set. For example, if equities have outperformed and now represent a larger share of your portfolio than planned, drift will be positive. This calculation is for educational illustration and does not account for transaction costs, timing considerations, or other portfolio dynamics.
Quick answer: with the default values, the result is 8.00 percentage points (Allocation Drift). Adjust the values below for your own figures.
Enter Values
People also use
Investing
Portfolio Rebalancing Calculator
Calculate the rebalancing trades needed to return your portfolio to a target asset allocation from current stock and bond holdings.
Investing
Portfolio Rebalancing Frequency Calculator
Estimate the annual transaction cost of rebalancing a portfolio at a chosen frequency — enter how often you rebalance and the cost per rebalance.
Crypto
Digital Asset Portfolio Calculator
Calculate how much of each digital asset to buy or sell to reach target allocation percentages. Enter asset 1 current value to see trades needed to rebalance.
Formula Used
Disclaimer
Results are estimates for educational purposes only. They do not constitute financial advice. Consult a qualified professional before making financial decisions.
Target 60% equity / 40% bonds, current 68% / 32%: 8 percentage point drift. Threshold-based rebalancing typically 5% drift triggers action. Under 5% is commonly treated as within tolerance; 10%+ is often treated as a trigger — extended drift changes the risk profile meaningfully.
Quick example
With current equity of 68% and target equity of 60% (plus rebalance threshold of 5%), the result is 8.00 percentage points. Change any figure and watch the output shift — it's often more useful to see the pattern than to memorise the formula.
Which inputs matter most
You enter Current Equity %, Target Equity %, and Rebalance Threshold. Not every input has equal weight. Adjusting one input at a time toward extreme values shows which ones move the result most.
What's happening under the hood
Standard drift calculation. The formula is listed in full below. If the number looks off, you can retrace the calculation by hand — that's the point of showing the working.
Why run this
Running the numbers makes the trade-offs concrete. Small changes in the inputs can move the result more than intuition suggests, which is hard to judge without working it out.
What this doesn't capture
This is a simplified model that holds its assumptions constant. Real outcomes vary with market conditions, costs, taxes, and timing, so the figure is best read as one scenario rather than a forecast.
Where to go next
This calculation rarely sits alone in a planning exercise. If you're running these numbers, related tools include the portfolio rebalancing calculator, the portfolio rebalancing frequency calculator, and the digital asset portfolio calculator — each one answers a different question in the same territory.
Your portfolio has drifted 8.00 percentage points from the target allocation of 60%, currently at 68%.
Inputs
| Action | Above threshold |
|---|---|
| Current Equity | 68.00% |
| Target Equity | 60.00% |
| Threshold | 5.00% |
This example uses typical values for illustration. Adjust the inputs above to match a specific situation and see how the result changes.
Sources & Methodology
Methodology
The calculator computes allocation drift by taking the absolute difference between your current equity allocation percentage and your target allocation percentage. It then compares this drift value against your specified rebalance threshold. If the drift exceeds the threshold, the calculator flags that rebalancing may be warranted. The model assumes allocations remain static between review periods and does not account for transaction costs, tax implications, or the timing of market movements. It treats drift as a simple point-in-time measure and does not model the impact of repeated rebalancing on long-term returns or portfolio volatility. This calculation is a straightforward monitoring tool to identify when portfolio composition has drifted from its intended targets.
References
Frequently Asked Questions
Typical threshold?
Tax-efficient rebalance?
Volatile drift?
Age-based shift?
Related Calculators
Portfolio Rebalancing Calculator
Calculate the rebalancing trades needed to return your portfolio to a target asset allocation from current stock and bond holdings.
Portfolio Rebalancing Frequency Calculator
Estimate the annual transaction cost of rebalancing a portfolio at a chosen frequency — enter how often you rebalance and the cost per rebalance.
Digital Asset Portfolio Calculator
Calculate how much of each digital asset to buy or sell to reach target allocation percentages. Enter asset 1 current value to see trades needed to rebalance.
More Investing Calculators
Investing
100 Minus Age Asset Allocation Calculator
Calculate stock-vs-bond allocation using the 100-minus-age rule of thumb — see the suggested percentage split for any age you put in.
Investing
Active vs Passive Investing Calculator
Compare active versus passive investing over the long run. See how a percentage point of extra fees compounds into a wealth gap over decades.
Investing
Annuity Present Value Calculator
Calculate the present value of an ordinary annuity from regular payments, periodic rate, and the number of periods until the stream ends.
Investing
APR to APY Calculator
Convert APR to APY for any compounding frequency to see the true effective annual yield — what you actually earn (or pay) on a given quoted rate.
Investing
Art Investment Calculator
Calculate art investment net returns including insurance and carrying costs, given purchase price, current value, and length of holding period.
Investing
Asset Allocation Calculator
Calculate suggested portfolio asset allocation by age and risk tolerance (stocks/bonds/cash). Enter risk tolerance 1-10 to see suggested stock and bond.
Explore Other Financial Tools
Business & Startup
Delivery Driver Profit Calculator
Calculate delivery driver net profit after fuel, vehicle wear, and other expenses — the gig-economy take-home behind a quoted gross.
Crypto
Stablecoin Yield Calculator
Stablecoin yield calculator. Project yield on USDC, USDT, or DAI holdings at user-supplied APY — fiat-denominated math without crypto price volatility.
Major Purchases
Noise Cancelling Headphones ROI Calculator
Calculate your noise cancelling headphones ROI by entering cost, daily focus minutes gained, and hourly rate to find your break-even month.
Spotted something off?
Calculations or display — let us know.